Currently, chemically synthesized agricultural chemicals are mainly used to control and inhibit the development of plant pathogens.
However, such agrochemicals are limited in use since they lead to the destruction of the natural ecosystem and have a very high possibility to cause the chemical poisoning, carcinogensis, malformation and various diseases of the human body due to residual toxicity.
For this reason, studies on the development of low toxic, eco-friendly biological agrochemicals are now actively being conducted.
Korean Patent Registration No. 10-0257452 (entitled “a bacillus subtilis A405 strain producing an antibacterial peptide with plant disease control activity and a method for controlling plant diseases using the same) discloses a Bacillus subtilis A405 strain (KFCC-11024) producing an antibacterial peptide with plant disease control activity, and a method for controlling plant diseases characterized by spreading a microbial formulation containing this strain to the crop field to be controlled.
Meanwhile, powdery mildew is one of the main plant diseases, which develop and cause great damages to crops, such as strawberries, cucumbers and the like, which become the main income source of farmhouses. Particularly recently, fungi resistant to the existing agrochemicals frequently appear so often that controls of plant diseases only by chemical treatment methods encounter limitations in their effect.
Thus, in an attempt to control powdery mildew using biopesticides, methods using natural substances, microorganisms and the like have been suggested.
Korean Patent Laid-Open Publication No. 2002-0072813 (entitled “New Bacillus sp. CMB26 strain, production of lipopeptide using CMB26 strain, and germicide of plant fungal pathogens containing CMB26 strain and/or lipopeptide) discloses a novel microorganism bacillus sp. CMB26 (KFCC-11289) characterized by producing lipopeptide with the high activity to disable the spores and mycelia of molds, and an antifungal agent against plant mold fungi such as powdery mildew, Mycosphaerella melonis, Botryosphaeria dothidea, Fusarium oxysporum, Collectotrichum gloeosporum, Botrytis cinerea, phytophthora root rot, or Rhizoctonia solani. 
However, although a number of biological control agents showing antifungal activity in Bacillus sp. fungi as described above are now published, there is no report on microbial pesticide containing a Bacillus amyloliquefaciens strain, which has an excellent control effect against plant pathogens and at the same time, is inexpensive and safe.